1. Field of the Invention
The invention relates to a projector and, more particularly, to a projector in which a heat conducting member is disposed between a lens and an optical module.
2. Description of the Prior Art
Recently, projectors are getting more and more popular. With the capacity of video playing, projectors are applied not only for common office meetings, but also for various seminars or academic courses. Generally speaking, a conventional projector always has a cooling system using fans to blow outside air into a case of the projector, so as to cool heat source (e.g. lamp, optical engine and so on).
The lens of a conventional projector is divided into a front lens group and a rear lens group. During assembly, parts of the front lens group are exposed outside the case of the projector. The front lens group is connected to the optical engine. The rear lens group is disposed at the end of the front lens group and inserted into an opening of the optical engine. Since the development of the projector tends to high watt and high luminance gradually, the lens will generate more heat while operating. Generally speaking, for the sake of cost down and process simplification, the front lens group is made of plastic and the rear lens group is made of metal. Since the plastic is unfavorable for heat conduction, the rear lens group is inserted into the light engine, and there is no specific fan for cooling the lens, a focal length of the rear lens group will be affected due to thermal deflection in case of failure of timely cooling, and that will further cause thermal drift.
In order to dissipate heat from the rear lens group, there has been a body of the front lens group made of metal in the prior art to increase heat dissipation area. However, the metallic body of the front lens group not only increases cost but also still causes thermal drift for those high luminance projectors.